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Old 03-09-2006, 08:14 PM   #1
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Turbo Dyno Help

Hello,

My friend got a Turbo Dyno, and we were trying to tune our motors today.

We get inconsistant readings on the dyno. We're using set torque method, and set it up like described somewhere on the forums. We do a test on a motor, then we wait like 10-15 minutes and do another one, and so on. For some motors, the latter tests are better, for others they're worse and the RPM sometimes varies by like 1000 (for the same motor), sometimes it's really close between tests.

Could this be because of our slave motor? The brushes are kinda worn.
What standup brushes should we use with it?

I mean we certainly could discern a bad motor (22,000RPM) at 3.0 torque when the other motors had like 26,000 but we were hoping for greater accuracy, this way it's impossible to differentiate a "better" motor from the "good" motors, if the readings aren't pretty close from test to test.

Oh also, we always use the auto-mode, because we tried doing manual mode once and the RPM readings WOULDN'T STABILIZE. They kept going down. Could the brushes cause all this?

Any recommendations or help would be appreciated.

Thanks!

-JMaggs
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Old 03-09-2006, 08:39 PM   #2
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I would definately rebuild the slave motor first. I'd use low silver hard brushes.

I always went by the motto: "If it hits 100 [email protected] 20amps, and 128watts @28 amps your golden...for stock motors anyways. The RPM is merely a gearing tool.
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Old 03-09-2006, 09:58 PM   #3
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Absolutely rebuild the slave motor (cut the comm, fresh low-silver brushes, etc. as mentioned above)...

ALSO -- make sure that the wires from the slave do NOT bind or rub on the sides of "hole" in the base where they come up to the slave. If there is any bind or rub, the readings can be erratic on torque...

As to RPM, CAREFULLY check/clean (with a q-tip and some rubbing alcohol) the small LED "eye" (just below the slave-test motor coupler) It MUST be is CLEAN.

Finally, make sure the end of the coupler that has the silver flat spot is clean and that the rest of that end of the coupler is uniformly BLACK and non-reflective.

The last two items can make RPM readings inconsistent. If the LED eye gets dirty, RPM readings can become totally weird!
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Old 03-10-2006, 12:21 AM   #4
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Hi, probably this question has already been answered. I just didn't want to read through the whole web site, I've got a lot of information in the past for setting up my TC4 and now my x-ray doing very well am happy. I want to get into building my own motors. Can someone tell me what equipment that I would need, not rich but only good stuff I don't want to have to buy a second time. So i appreciated if you can give me the names of the equipment that I need . Not much for it can say but appreciate any information.
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Old 03-10-2006, 07:47 AM   #5
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If you test in manual mode, you will almost always see the RPM drop when using either amp or torque settings. It will do this because you're heating up the brushes and armature. I normally run a few pulls on the dyno so that I can see how much the motor will fall off when it gets hot.

I would use some of the new long wear brushes in the slave motor. The stand-up Trinity XXX brush should work really well and last a long time. A cheaper alternative would be the Reedy Quasar stand-ups.

Just a note, there will always be some variation from run to run. There are so many things that can make the motor vary from run to run that it's hard to split hairs with the dyno. Mainly brush wear, alignment, comm condition and how hard you press down on the motor. Don't press down hard but keep it from rotating in the nest.
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Old 03-10-2006, 09:13 AM   #6
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Quote:
Originally Posted by rc10bob
I want to get into building my own motors. Can someone tell me what equipment that I would need, not rich but only good stuff I don't want to have to buy a second time.
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Old 03-10-2006, 10:42 AM   #7
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Quote:
Originally Posted by rc10bob
Hi, probably this question has already been answered. I just didn't want to read through the whole web site, I've got a lot of information in the past for setting up my TC4 and now my x-ray doing very well am happy. I want to get into building my own motors. Can someone tell me what equipment that I would need, not rich but only good stuff I don't want to have to buy a second time. So i appreciated if you can give me the names of the equipment that I need . Not much for it can say but appreciate any information.
For starters, get a "Fiddlestick" (as a second choice, get the similar spring tension tester from Trinity)... One key to consistent motor performance is KNOWING how stiff/soft the springs are... Not all "reds" or "greens" or "purples" are the same, even from the same manuf. (like Trinity) these small testers REALLY help you out...

Some form of brush serrator/cutter tool will help too. You can reserrate to regain performance without replacing brushes, you can make "cuts", etc. to adjust brush wrap, etc. more consistently than by hand...

If all else fails, the TRACK is the best "dyno" -- I have an Orion LCS lap counter that lets me time my practice runs. I can download detailed lap times into a laptop, see a graph of performance (did the motor fall off at the end, etc.)... Expensive, but VERY valuable -- not just for motor tuning, but also for chassis tuning and for trying different "lines". WORTH EVERY PENNY!

Even though I have a Turbo Dyno for my "real" motor testing, they are EXPENSIVE! and harder to justify....

I do also own an Integy "Dyno v2", which is a WONDERFUL tool for seating brushes and similar "break in" tasks. Well worth the money.

Buy a quality brush post wrench (my favorite is one from Integy) -- makes it much easier to loosen brush hoods for "tweaking"...
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